This invention relates to a self-opener closure for composite packaging as well as for container spouts or bottle spouts of all types to be closed with film material. At the same time one specifically envisages liquid packagings in the form of such composite packagings of film-coated paper in which milk, fruit juices, all types of non-alcoholic drinks or generally fluids also in the non-food range are packaged. The closure may however also be applied to composite packagings in which goods capable of being poured such as sugar, semolina or all types of chemicals and likewise are kept or packaged. With this film-coated paper it is the case of a laminate material such as a paper or cardboard web coated with plastic such as for example polyethylene and/or aluminium. Usually volumes of such packagings range from 20 cl up to 2 liters and more. Alternatively the self-opener closure may also be assembled on containers which are closed by a film material, such as on all types of bottles of glass or plastic or on similar containers. Such closures of plastic are known in various embodiment forms. If they are envisaged for composite packaging they essentially form a pour-out spout with a shoulder which radially projects from its lower edge and which forms a closing flange on this pour-out spout. The spout is equipped with an outer thread onto which a threaded cap may be screwed as a closure. Such a self-opener closure is flanged onto the composite packaging in that it is sealingly welded onto the composite packaging with the lower side of its projecting edge, thus with the lower side of its flange. The free passage at the lower end of the spout is thereafter closed by paper and the sealing film of the composite packaging. In the case of a bottle closure the pour-out spout for its part may be placed or screwed onto the opening of the bottle, and on its inner side is closed with a film membrane. The spout is equipped with an outer thread onto which the threaded cap may be screwed as a closure.
The film-reinforced paper passing through and below the welded-on spout, or the film membrane running within the spout must be cut open or torn open towards the opening or pressed away from this so that the passage may be released and the fluid or the pourable material may be poured or shaken out of the container through the spout. For this a sleeve is arranged within the spout which on rotating the screwed-on cap is caught by this and thus is rotated by this in the same direction of rotation. By way of a thread counter rotating to the thread on the outer side of the spout and on the outer side of the sleeve this sleeve moves continuously downwards on screwing off the threaded cap, that is to say if one displaces this upwards with respect to the liquid packaging. The lower edge of the sleeve is equipped with one or more tearing or cutting teeth. By way of this as a result of its rotation and constant downwards movement the sleeve is to press out or cut out a disk from the film-reinforced paper or the film membrane here, which runs beneath it.
Such conventional self-opener closures however do not function satisfactorily. The disks are not cut cleanly from the paper film or the film membrane, but rather the sleeve simply presses a piece of film out of this. The remaining edge is frayed and thus shreds of paper or film project into the passage which is supposed to be released open. These shreds often project downwards into the container and on pouring or shaking out possibly block the path of the outflowing jet of liquid or the shaken-out goods. With larger packagings with stronger film-reinforced paper or cardboard the opening procedure is carried out even less reliably and cleanly. The sleeve which moves slowly downwards and rotates simultaneously, with its complete lower edge quasi simultaneously contacts the film-reinforced paper web to be cut open and as a whole presses it downwards and rotates on it until a hole is scraped open or broken through rather than cleanly cut open. A cause of problem as to why the cutting-open is not effected cleanly amongst other things lies in the fact that the film to be cut open somewhat downwardly evades the pressure of the sleeve acting to a certain extent as a drill bit, and thus the sleeve no longer acts on a plane paper film but on one which is curved downwards.
The previous solutions, as a result of the design of the sleeves which usefully may be described as a penetrator because indeed they penetrate a paper film piece rather than cleanly cutting a circular disk out of it, demand a significant force on the part of the user. Specifically a large torque must be exerted since the teeth or tearers on the lower penetrator edge or sleeve edge firstly merely scratch the film firstly along the whole edge of the sleeve and then a large rotation resistance must be overcome. In the uppermost layer of the paper thickness they act similar to tear-open teeth, specifically in a scraping, pressing and tearing manner rather than acting as an actual cutting blade.
In order to simplify the breaking-out or tearing-out, for the conventional self-opener closures of this type the film material or the composite material is pre-weakened at the desired tear locations by way of lasers or punching tools. This pre-weakening however entails much technological effort. One requires very expensive installations and the handling for the machining of the penetration locations on the films is time-consuming. In spite of these complicated weakening measures the conventional self-opener closures do not cut cleanly, but tear the paper or plastic film rather than cleanly cutting it open, which explains the large resistance to rotation. On account of these large rotation resistances even breakage of the means which assume the transmission or the torque from the threaded cap to the penetrator sleeve occur, or the provided catching cams which engage into grooves on the penetrator sleeve jump out of these grooves. If this happens the self-opener closure is no longer capable of functioning. A further problem lies in the fact that the torn-out or partly cut-out film disk is folded downwards by the penetrator sleeve much too little, or the film disk over the period of use of the closure remains folded too little downwards since the penetrator sleeve is not securely fixed in its end position.
All these problems are to be solved by a proper self-opener closure. It would furthermore be desirable in one variant to have a self-opener closure which would allow the automatic metering of a small quantity of substance in solid, liquid, granular or powder form separate to the contents of the composite packaging as soon as the closure is opened, or which would effect the metering of such a separate substance in solid form when pouring out, in that the substance is poured over by the pour-out jet and washed out.